Cause

You created a terminal without terminal strip definition in the terminal strip navigator or placed it in the schematic.

Solution

Possibility 1

Select the New popup menu item in the terminal strip navigator.

In the expanded Selection tree of the subsequent dialog (via Electrical engineering > Terminals and plugs > Terminal strip definition > Terminal strip definition), navigate to the Terminal strip definition function definition. Click [OK], and assign it the displayed DT of the terminal in the Properties <...> dialog.

Possibility 2

Use Insert > Terminal strip definition to place a terminal strip definition in the schematic and use the Properties <...> dialog to assign the displayed DT of the terminal to it.

Then start a new check run.